Some existing displays are made of a light guide with edge light sources. However, almost all the displays are not transparent enough for window applications. A smart window available today is able for transparency adjustment. The smart window can thus save energy by blocking external heat in the summer time. Some of them are also able for serving as a display. It can be used as a curtain for shielding and preventing outsiders peeking in. However, when the smart window is in its blocking mode, it is not possible for an insider to see out. It is neither able to adjust ambient light when outdoor light intensity is sufficient or insufficient. Therefore, there is a need to design a smart window, or an intelligent, multifunction ambient light adjustment apparatus to overcome the above mentioned shortcomings.